Telephone-reciever.



c. MASON; v TELEPHONE RECEIVER. APPLICATION EILEDSEPT. 12, 19AM.

Patented 111113151912.

Pisa;

F-BG.3.

INVENTOIL 7 A TTORNEX I snap CHARLES TVIV IASON, OF fiUMTER SOUTH CAROLINA, ASSIGNORTO THE SUMTER TELE- PHONE MA1\T UFAC'I'URIN G 00., A CORPORATION OF SOUTFH CAROLINA.

. TELEPHONE-RECEIVER.

resign.

Specification of Letters latent.

Application filedSepte nber 12, 1910. Serial No. 581,611

To all whom it may concern:

the following to be a full, clear,'and exact description of 'the invention, such as will enable others skilled in the art to which it appertains to make and use the same,-reference being had to the accompanying draw ings, and to the letters and figures of refer- .ence marked thereon, Wl11Cl1 form a part of this specification.

My invention relates to telephone receivers, and consists of means whereby the operative part of the instrument is incased in I a metallic shell which holds the parts firmly receivers may be used.

in position, and obviates the expense and troublecaused by the breakage of rubber or other shells heretofore used and the cost of replacing same. I

I further provide means for insulating the working parts and the conducting cord from the metallic shell so that it is not only impossible for the user to receiye an electrical shock from handling the instrument,

but contact between themetallic shell and thetelephone switch hook is prevented.

I also provide a simple and cheap form of adjustment, thereby cheapening the manufacturingcost, Y

In the accompanying drawing, Figure 1 is a vertical longitudinal view partly in section, of a receiver illustrating my invention. Fig. 2 is a front View of a receiver hanging on a telephone switch hook lever. I Fig. 3 is a side View of the receiver and switch hook, the switch hook lever being shown partly in section.

Referring to Fig. 1, I provide the usual magnet structure 1 supporting theinsulating block 2, carrying the cord terminals 8,

the structure 1 also supporting the pole pieces and magnet coils 4. This structure is the preferred form, but any of the well known forms commercially used in telephone form shown in the drawing,. the threaded block 5 is bolted'to magnet 1 bymeanscf screw 6, block 5 being screwed into the insulating piece 7 It'will be observed that. by

screwing the piece 5 up or down in piece 7, the adjustment betweent-he pole pieces and In the preferred coils t and the diaphragm 5 may be easily and accurately accomplished thereby obviating the'fil ing and accurate adjustment of the pole pieces heretofore necessary. Insulating piece 7 is so shaped that it snugly fits into the metallic casing 8, andsupports the various parts of the receiver structure so that none of them come in direct contact with metallic shell 8, but the entire structure isreadily removable from the shell 8 as it is not attached to same in anyway.

To provide means for securely holding diaphragm 5 in position I thread the rim of piece '7 as shown at 9, and screw thereon the auxiliary cap shown at 10, thereby clampingthe diaphragm 5 firmly to the end of piece 7. To insulate cap 10 and the diaphragm from cap 11 of the metallic shell. I provide an insulating'lining 12. The rim of the shell 8 is threaded and ap 11 of metal or any suitablev material is screwed thereon, this serving -to hold the unit'structure just described securely in place. The

conducting cord 13 is brought in through an insulating end pieceshown in section at let. This is secured by fihreads or other suitable means 15 to the me allic shell 8.

From the foregoing it will be seen that the cord, the receiver structure, and the diaphragm, are insulated, from the metallic casing at points 7, 12, and 14, therefore, should the electrical circuit through the cord 13 or coils 4 come in contact with the metal parts of theinstrument, it would be -confined thereto, the outer shell 8 and cap- 11 being insulated at all points.

In many telephones the receiver hook switch upon which the receiver hangs when not in use, forms-a part of .the telephone circuit, or is only lightly insulated therefrom by thin fiber insulation. This being the case, if the metallic shell 8 of the receiver should accidentally become connected .to one side of the-telephone circuit, and the hook to the other side, whenthe'recciver is hung on the hook, it'will cause a disarrangement of the telephone circuits, or when the hook is but thinly insulated, a condition of electrical stress would exist between the hook and shell which would tend to break down the. thin insulation To prevent trouble from this source I so shape the iusulating piece H'that when the receiver In hanging on the hook lever '16 as shown in Fig; 2, the lever comesin contact with the insulating piece at points 1 7, and the-metallic casing 8 does not'touch the lever, a clear space being left all around as shown at 18,

I am aware that it is not-new ina telephone receiver to provide a metal case, but 1 claim that it is new to have the cord and the operative parts of the receiverinsulated from the metal casing and to have said parts removable from the casing wlthout disturbing the ad ustment or the diaphragm or removing any screws, and while I have shown only onetorm of construction, it will be understood that various other forms and methods of assembling can be used without departing: from the essential features of my invention.

Therefore, having described my invention, Iclaim and desire to secure by Letters Patent'the following: i

1. In a telephone receiver, the combina-' tion of an insulating body, a diaphragm clamped thereon, an adjustable'block carrying a receiver structure fittinginto said 1n sulating b dy, a metal casing carrying a piece of insulating material on one end and a detachable cap lined" with insulating material on the other.

2. In a telephone receiver, an insulating body, a threaded support carrying the receiver parts and adjustable in said body, a diaphragm and means for clamping same to the insulating body, a terminal block and a conducting cord attached thereto, and a metallic casing insulated from the cord and receiver structure, substantially as described.

3. In a telephone receiver a metal. case having an insulating tail piece attached to one end, and a metal cap to the other, a magnet structure and coils, pole pieces and cord terminals, a block adjustable in an insulating'casing, supporting said pieces and terminals, a diaphragm secured to said insulating casing by a threaded cap, and insulation between said diaphragm cap and the outer metal cap.

i. A unit receiver mechanism, diaphragm,

and cord, and means for holding them in ing having its remaining portion arranged to come flush and conform with the outside surface of said shell and elongated and enlarged so as to form a means for supporting insulating and spacing said shell from a receiver hook, said bushing being pro vided with a passage whereby the receiver I cord may pass therethrough and beinsulated and spaced from said shell.

In testimony-whereof I hereunto aflix my signature in the presence of two witnesses. CHARLES T. MASON.

Witnesses:

F. G. MAN ING E. M. HALL. 

